Getting it home intact
Updated
More specimens are broken between the face and the car than anywhere else in the process.
The walk is the dangerous part
Material in a bucket knocks against itself with every step, on ground that is by definition rough.
Wrap at the face. A specimen wrapped where you found it survives the walk; one thrown in loose to be sorted at the car does not.
And carry less. An overloaded pack on loose ground is how people fall, which is a worse outcome than a broken specimen.
In the pack
Each piece wrapped separately, heavy at the bottom and against your back.
Fragile pieces in a rigid container inside the pack, not padded in among the rest.
Nothing loose. A single unwrapped cobble rolling among wrapped specimens undoes the wrapping.
In the vehicle
The two problems are movement and heat.
Boxes wedged so they cannot slide, low, not stacked high.
And out of the sun. A boot in summer cycles through temperatures no interior reaches, which is thermal shock plus a humidity swing on material that is often still damp.
A day at a show with the stock in the car is the same problem and it is more common.
Unpacking
The same day, or at least the same week, while you still remember which bag was which.
Let material reach room temperature before washing anything. A cold specimen in warm water cracks.
Transfer the locality from the wrapping onto a real label before the paper goes in the bin, which is the moment most locality data is lost.
And the newspaper comes off. It is transit packing and it is acidic.